AA batteries in A80

I bought a Canon A80 three days ago. It is my first digital camera which I intend to use in my future travels. It replaces my old Nikon 8008S. As I read the User Guide, I came accross this statement, "Never use manganese or lithium batteries, as these battery types may overheat in the camera". The Sales Associate where I bought the camera and batteries suggested I use these batteries because they last much longer. They are not the rechargeable type. I called the store where I made this purchase and the Sales Associate stated that I could absolutely use this type of battery.

Is this a 'CYA' statement from the manufacturer, or is it a valid warning?

I'm not sure what a "CYA" statement is. I expect those batteries will work fine. They might void your warranty since they made a specific statement about them, though. If it were me, I'd get a few sets of rechargeable NiMh batteries. They might not last as long as lithiums, but the good ones do last a long time and if you have a few sets it's not a big deal. Plus, you'll save money in the long run.